1 files changed, 4 insertions, 1 deletions
diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp
index e4c380ae0ed..f2eb4e642be 100644
--- a/clang/lib/Frontend/InitPreprocessor.cpp
+++ b/clang/lib/Frontend/InitPreprocessor.cpp
@@ -137,7 +137,10 @@ static void DefineFloatMacros(MacroBuilder &Builder, llvm::StringRef Prefix,
                "1.79769313486231580793728971405301e+308L",
                "1.18973149535723176508575932662800702e+4932L");
 
-  llvm::Twine DefPrefix = "__" + Prefix + "_";
+  llvm::SmallString<32> DefPrefix;
+  DefPrefix = "__";
+  DefPrefix += Prefix;
+  DefPrefix += "_";
 
   Builder.defineMacro(DefPrefix + "DENORM_MIN__", DenormMin);
   Builder.defineMacro(DefPrefix + "HAS_DENORM__");